For eye examining instruments that contact a cornea, it is desirable to discard and replace a cornea contactor after it has become wetted with tears of a pair of eyes being examined. Discarding used cornea contactors can prevent transfer of bacteria, viruses or prions from one patient to another. For this purpose, our previous U.S. Pat. Nos. 5,070,875, 6,179,779, and 6,471,647 and our pending application Ser. Nos. 09/811,709 and 10/178,987 have suggested a few ways of making tonometer prisms readily replaceable. The desirability of replacing cornea contactors is not limited to tonometers or prisms, though. As revealed in our application Ser. No. 10/178,987, eye contacting cornea contactors are also useable in opthalmologic instruments examining eyes for purposes other than tonometry. Also, corneal contactors are not limited to prisms, and can be formed as windows or other light transmitting elements that contact a cornea for examination purposes.